Starting crank for internal-combustion engines



A. BEAUBIEN July 16, 1929.

STARTING'CRANK FOR INTERNAL COMBUSTION ENGINES Filed April 18, 1928INVENT'OR HLPHONSE BEAUB IEN RTTORNEYS Patented July 16, 1929.

UNITED STATES PATENT OFFICE.

STARTING CRANK FOR INTERNAL-COMBUSTION ENGINES.

Application filed April 18,

My invention relates to improvements in starting cranks for internalcombustion engines, which are particularly adapted for use on tractors,motor boats and the like. The objects of the invention are to providemeans whereby the reverse movement of the engine shaft due to backfiring is not communicated to the handle of the starting crank.

The invention consists essentially of a shaft adapted to be fitted tothe crank shaft of an engine, a hand crank for said shaft having africtional grip interposed between them, whereby the rotation of thecrank imparts corresponding rotation to the shaft until a predeterminedresistance to rotation is encountered, as will be more fully describedin the following specification, and shown in the accompanying drawings,in which Fig. 1 is a front view, partly in section, of the crankmechanism.

Fig. 2 is a section through the radiator of a tractor showing thestarting crank fitted to the engine crank shaft.

Fig. 8 is a front View showing the crank and the annular rack with whichit engages.

In the drawings like characters of refer-- ence indicate correspondingparts in each figure.

The numeral 1 indicates the forward end of an engine crank shaft havingthe usual dog clutch 2, which is adapted to be engaged by the startingcrank. The numeral 3 indicates a radiator on the front of which ismounted an annular saw tooth rack 4 the purpose of which willhereinafter appear.

The numeral 5 indicates generally a start-- ing crank which is formedwith a shaft 6 having at its free end a transverse pin 7 by whichengagement is effected with the clutch 2 of the engine shaft 1. Theshaft 6 is journalled between two plates forming a housing 8 and isfitted with an oval cam 9. Extending from v the housing 8 is a handcrank 10 and pivotally mounted therein as at 11 is a pair of opposedgripping levers 12 which are curved intermediate their length to conformto the sides 13 of the cam 9. The free ends of the levers 12 are eyed asat 14 and support a bolt 15 which is provided at one or both ends Withbutterfly nuts 16 for the purpose of forming abutments to one or moresprings 17, which springs are so compressed as to hold the levers 12 infirm contact with the peripheral faces 1928. Serial No. 270,943.

of the cam 9. Mounted upon the underside of the housing 8 is a springpressed pawl 18 which is adapted to engage the annular rack 4 to permitthe crank 10 to rotate in a clockwise direction and to prevent itsrotation in an opposite direction.

In operation the shaft 6 is engaged with the engine shaft 1 in the usualway and as the hand crank 10 is turned, the levers 12 are spread apartby partially turning about the cam 9 due to the resistance to rotationof the engine shaft substantially as shown in dotted line in Figure 1.As soon as the resistance afforded bv the springs 17 to the spreadingapart of the lovers becomes greater than the resistance of the engineshaft to rotation, the cam 9 will be held stationary between the leversand the. continued rotational movement of the hand crank will becommunicated through the shaft 6 to the engine shaft 1. If insufficientresistance is imposed to the rotation of the cam between the levers, thebutterfly nuts 16 are tightened up upon the bolt 15 as may be required.

During the turning movement of the hand crank in a starting direction,the pawl 18 is being drawn along the teeth of the annular rack 4, but assoon as a back fire occurs the pawl engages one of the rack teeth,preventing the hand crank from being rotated in the opposite direction,simultaneously the engine shaft imparts rotation through the shaft (3 tothe cam 9, causing the levers 12 to be thrown apart as the longer axisof said cam is moved to a position transverse to the levers and allowingthem to move back to normal position as the shorter axis reaches asimilar position relative to said levers. The lever movement thusdescribed will continue so long as the engine is turning contrary to itsnormal running direction.

What I claim as my invention is:

1. A starting crank for internal combustion engines comprising a shaftadapted to be releasibly fitted to the shaft of the engine, said shaftbeing fitted with a cam and being journalled in a hand crank housing, ahan dle to the housing and a spring tensioned means carried by thehousing engaging the cam for imposing a resistance to the rotation ofthe shaft sufficient to overcome the resistance to rotation of theengine shaft.

2. A starting crank for internal combustion en 'ines comprising a shaftadapted to be releasably fitted to the shaft of the engine,

said shaft being fitted with a cam and being journalled in a hand crankhousing, a handle to the housing and a spring tensioned lever curved toconform substantially to a portion of the cam and in engagementtherewith whereby a resistance is imposed to the rotation of the shaftsutficient to overcome the resistance to rotation of the engine shaft.

Dated at Vancouver, B. O, this 5th day of April, 1928.

BEEN

